A flame burning at the top of one of the
plant’s highest towers might look alarming,
but in fact it is an important part of its
operation. It is not uncommon for people
to be concerned when they see smoke or
flames coming from the tower, called the
flare stack.
However, the flare is a normal and vital part
of keeping the plant running safely during
unplanned operational interruptions or
scheduled maintenance.
How does the flare work?
The flare acts as a safety valve for the
plant. During normal operations, crude oil
is refined to produce a variety of products.
However, during an interruption, such as
an unplanned loss of power, the system
is occasionally unable to continue its
processing and excess hydrocarbons are
routed through the flare system.
There, the vapours are combined with
steam and burned off; ensuring maximum
combustion of hydrocarbons, while
minimising emissions into the air.
Reflection off the clouds
The Fawley site has four flare stacks. When
used on cloudy nights, light from the flares
can reflect off the clouds, which can then
be seen in the local communities.
What is that rumbling noise?
Flaring can occasionally lead to a rumbling
sound, similar to distant thunder, resonating
from the system. The rumbling is the result
of the turbulent mixing of vapours during
the flaring process.
It is similar to the sound you hear when
you fan a fire and the flame mixes with the
added oxygen.
What is that black smoke?
Black smoke from the flare occurs when
there isn’t enough steam to help burn
the hydrocarbons sent to the flare. Site
personnel are constantly monitoring the
flare to ensure that steam levels are correct.
In the rare instance of a sudden release of
hydrocarbons to the system, there may be a
delay in response before enough steam can
be supplied to the burning process and black
smoke may be emitted for a short time.
Regulating emissions
The Environment Agency strictly regulates
emissions from the site including noise.
In recent years, we have taken a number
of steps to recover and reprocess excess
materials to lessen day-to-day flaring. We
have also invested in improvements to the
flare system to reduce noise and smoke.
However, use of the flare system is still
essential to the safe operation of the plant.
For more information, contact the
Community Affairs department at
ExxonMobil at Fawley on 02380 892511
or email ExxonMobilFawleyPAStaff@
exxonmobil.com
Facts about the Fawley refining and petrochemical complex flare system
A flare for safety
Image: One of the
four flare stacks
at ExxonMobil at
Fawley.